Pet drinking fountain design



FIG. 1 is a top perspective view of a pet drinking fountain showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a right side elevational view thereof, the left side elevational view being a mirror image thereof; and,

FIG. 4 is a top plan view thereof. 

The ornamental design for a pet drinking fountain design, as shown and described. 